Punch press



E. SASS PUNCH PRESS Nov. 29, 1932.

Filed May 27. 1929 2 Sheets-Sheet 1 A Ff/7265K im fww% Nov; 29, 1932. E. SASS PUNCH PRESS Filed May 27. 1929 2 Sheets-Sheet 2 fill, llllllill IIIAIII.

Patented Nov. 29, 1932 UNITED STATES PATENT ori-*ice- ERNEST SASS, OF AURORA, ILLINOIS PUNCH j PRESS Application mea May '27,

10 able punch considerable accuracy and some delay is required in operating the pressand in bringing the prick marks into accurate register with the center point of the punch. AI have found that these objections can be 15 avoided by employing an upper fixedpunch and a lower movable die.

By this construction the work can be disposed closely adjacent the'punch by slightly raising the die so as to bring the punch point .29 into register with the prick mark, the die serving to support the Work as it is moved upwardly for punching out the metal. A

press constructed in this manner can be operated more accurately and at higher speed 5 than presses of ordinary type now in common use, as above referred to. One of the main objects of my invention is t'o Aprovide a press of light, but strong, and durable construction particularly adapted to be operated by foot power and to be secured to a bench or similar supporting structure. A further object is to provide a press of this character of comparative simple and inexpensive construction having associated with the Vpunch stripping means for stripping the work therefrom. Another object is to provide simple and highly efficient operating means adapted to permit adjustment of the press head to suit working conditions. Further objects and advantages of my invention will appear from the detailed description.

In the drawings:

Figure 1 is a side view, partly broken away and in section, of a pressY constructed in accordance with my invention, as applied to a work bench,

Figure 2 is a plan view of the press head,

Figure 3 is a front view of the ,press head, and associated parts, partly broken away and -a-section,

1929. 'serial No. 366,207.

Figure 4 is a detail sectional view of the yielding connection interposed in the operating rod,

Figure 5 is a fragmentary sectional view through the die and the head, illustrating the relation therebetween during the punching operation, the punch being shown in elevat-ion, and;

Figure 6 is a section taken substantially on line 6 6 of Figure 1. 60

In Figure 1 of the drawings I have illusy trated a press lconstructed in accordance with my invention as applied to a work bench 1, the press being secured to the bench by a strap 2 which passes about tubular column 3 of thev press and is secured to the edge of the bench by screws, `in a known manner. Preferably a set screw 1l is threaded through strap 2 and bears against column 3 to prevent any objectionable looseness of play thereof in the strap. The lower end of column Sthreads into the upper end of a standard 5 which is preferably of circular cross section and is provided at its lower end with a base flange 6 having suitably spaced openings for reception of Vbelts 7 by means of which the base flange is anchored to a suitable foundation 8.

Standard 5 is bored out fromits upper end for` reception of a tubular plunger 9 in the lower end of which is secured a plug 10. This plug is provided, at its lower end, with a Vrounded head 11 which contacts a cam 12 on the upper edge of an operating lever 13 which is-iockably mounted, by means of a pivot bolt 14E, through a slot 15 extending diametrically through the standard 5. A counterweight 16 is adjustably secured on the lever in a known manner, at one side of the fulcrum thereof, and a foot plate 17 is rockably secured, by'a pivot bolt 18, to the other end of the lever.

1 A collar 19 is secured about plunger 9, adjacent the upper end thereof, and fits snugly within standard 3, this collar serving to guide the plunger and prevent objectionable looseness or play of the upper end portion thereof. 95 The `upper end of column 3 is exteriorly threaded for reception of a socket member 2O depending from a press head 21 of'approximately U-shape, this head being, in general, Y 'of vknown type. A set screw 55 is threaded 100 through socket member 2O and engages the column 3 for securing the press head in ad* justment thereon. The socket member 20 is provided with a reduce bore extending from the upper end thereof, this bore receiving a cylindrical die 22 having a central die opening 23 for cooperation with a punch 24 for punching out the metal of selected areas of a sheet.

The die 22 seats upon the upper end of plunger 9 so as to move therewith.

The other arm of press head 21 is provided with an enlargement constituting a barrel 25 which is axially bored from its lower end and slidably receives punch 24. As will be noted more clearly from Figure 3, the barrel is bored and threaded from its upper end for reception of a bolt 26 the lower end of which may be reduced at 26a to extend into the bore which receives the punch. The upper end of the punch contacts the lower end of the bolt which thus constitutes an abutment member for limiting insert-ion of the punch into barrel 25. After the punch has been properly positioned it is secured by a setscrew 27.

The upper arm of head 21 is also provided, contiguous to barrel 25, with a laterally projecting enlargement or boss 23. This boss is provided, in one lateral face thereof, with a vertically extending groove 29 of rectangular cross section. which slidably receives a similarly shaped stem 30 of a stripper 31. This stripper is of L-shape and is provided, at its lower end, with a fork 32 which straddles the lower end portion of punch 24. The stem of the stripper is held against outward movement in the groove 29 by strap plates 33 set on the outer face of projection 23 and bridging the groove, these plates being secured in position by screws 34.

A, lever 35 is pivotally mounted on a pivot screw 36, passing through a bracket 37 secured to projection 28, and screwing into the projection. This bracket opens downwardly to permit ready removal and replacement of the lever when desired or necessary. At its forward end the lever is pivoted, at 38, to stem 3() of the stripper. This connection between the lever and the stripper is sufficiently loose to permit of the required movement of the stripper without binding of parts and, if desired, may be a. pin and slot connection. The other end of lever 35 is pivoted, at 39, in a clevis 40 secured on the upper end of an operating rod 41. This rod comprises an upper section 42 and a. lower section 43, and a yielding connection 44. Referring more particularly to Figure 4, this yielding connection comprises a cylindrical tubular body 45 and heads 46 and 47 having reduced threaded necks which are screwed into the ends of the body. Section 43 of the rod is screwed into head 46 and has its lower end portion bent at right angles to provide a finger 48 which projects through lever 13, a Cotter pin or equivalent member 49 being inserted through the finger to prevent withdrawal thereof from the lever. Rod section 42 extends through a relatively large opening 50 in head 47 and is provided at its lower end with a disc 51 suitably secured thereon and fitting the interior of body 45 loosely.

An expansion coil spring 52 is disposed about rod section 42 and is confined between head 47 and disc 51. The opening through which finger 48 extends is of appreciably greater diameter than the finger thus providing a desirable looseness in this connection.

t is also to be noted that the disc 51 is of somewhat less diameter than the interior of member 45 which, in conjunction with the relatively large opening 50 for rod 42, permits a certain amount of rocking movement between the two sections of rod 41. I thus provide a suitable operating connection between the lever 13 and lever 35 by means of which the head 21 can be adjusted about the column 3 through an arc of 45 degrees or more in either direction from the position of the head illustrated in Figure 1 without interfering with proper operating connections between the levers.

In the use of the press, sheet metal which has been marked with a prick punch as previously referred to, is fed over a table or board in a known manner above die 22 and provided with an opening to accommodate the guide. Thisl disposes the sheet metal closely adjacent the point ofthe punch which, at this time, is projected slightly beyond the fork of the stripper by depressing the outer end of lever 13 to the proper extent. As a prick mark on the sheet metal is brought into register with the point of the punch, the outer end of lever 13 is .pressed down quickly thus swinging the weight 1G upwardly.

This projects plunger 9 upwardly, by means of cam 12, thus raising the die 22 into operating relation to punch 24 so as to cause the punch to punch out of the sheet a. disc of metal to provide the desired opening therein. Obviously, the punch is of desired shape to cut openings of desired size and shape. Due to the provision of weight 6, the sudden downward pressure on the outer end of lever 13 results in the weight 16 swinging upwardly, due to inertia, an appreciable distance and at such a rate as to apply pressure to plunger 9 with sufficient force to cause punch 24 to penetrate the work with but little effort on the part of the operator.

Upon release of the pressure applied to foot plate 17, plate 16 acts to return lever 13 to its normal position illustrated in Figure 1. During the depression of the outer end of lever 13, spring 52 is compressed, to a certain extent, and the stripper is moved into its raised or inoperative position adjacent barrel 25 so as not to interfere with the upward movement of die 22. This position of the stripper is illustrated in Figure 5 in which the work or sheet of metal is indicated by S. luring the initial portion of the return movement ot the lever the spring expands until disc 5l contacts the reduced neck of head 46, after which rod section 42 moves upwardly with rod section 43 and lever 18, thus raising the outer end of lever 35.

rIhis depresses the stripper 30, the fork 32 of which straddles the punch, so as to move the stripper downwardly into the position of Figure l. In this manner the work is 1 stripped from the punch as the'die 22 is lowered, and lowering or downward movement of this die is facilitated by the pressure of the stripper on the upper face of the work. A punch press constructed in this manner can be readily produced at relatively small cost and is particularly adapted for application to a work bench or other structure of like nature. The adjustability of the head 2l is advantageous as enabling the head to be disposed so as to view the work to best advantage. By employing the cam and lever arrangement for operating the plunger 9, relatively great pressure is obtained at the die 22 for a given pressure exerted onthe foot plate 17. 'I'he punch press, as a whole, is of comparatively simple and inexpensive construction and is particularly adapted for use in sheet metal shops and similar establishments.

Lever 13 is provided with a bumper b of suitable construction, having an insert of rub- 4 bei', or other cushioning member disposed to contact the supporting surface upon depression of the lever beyond a predetermined extent.

IDlunger 9 is providedwith an opening 53 through which the slugs pass into a space 54 about the plunger, and thence to slot 15 through which the slugs are discharged.

lVhat I claim is:

l. In a punch press, a standard, a tubular column carried by the standard, a plunger mounted in the column for reciprocation therein, a head mounted upon the column, a die mounted in the head and having operating connection with the plunger, a punch mounted in the head in alignment with the die, a main operating lever mounted in the standard, operating connections between the lever and the plunger, a stripper associated with the punch, and operating connections between the stripper and the lever acting to operate the stripper similarly to the die.

2. In a punch press, a standard, a tubular column supported by the standard, an operating lever mounted on the standard, a plunger mounted within the column for vertical reciprocation, operating connections between the plunger and the lever, a head mounted upon the column and adjustable about the same, a die mounted in the head and having itsunder face in contact with the upper end of the plunger, a punchcarriedby the head and-disposed above' and in alignmentwith the die, a stripper mounted for vertical reciprocation and having stripping elements disposed adjacent the punch at opposite sides thereof, a stripper lever having one arm connected to the strip-per, and an operatingrod connecting the other arm of the stripper lever to the operatinglever, said rod including a loose yielding connection adapted to yield during movement of the operating lever inplunger raising direction, the stripper being operated similarly to the operationof `the plunger.

3. In a punch press, a standard, a tubular column mounted in the standard, an operating lever mounted inthe standard, a plunger mounted in the column for vertical reciprocation thereinand provided at its lower end with a pressure receiving element, the lever being provided with an upwardly extending cam contacting said element for raising'the plunger when the lever is operated in proper direction, a head mounted on the column, a -die mounted in the head for vertical movement and having its vunder face in contact with the upper end of the plunger, a punch mounted in the head above and in alignment withthe die, a stripper mounted on the head for vertical reciprocation and havingstripping elements at opposite lsides `of and adjacent the punch, and operating connections between the lever andthe stripper acting to raise the stripper'into inoperative position as the die is raised ,into operative relation to the punch and to move the stripper downwardly along the punch as the die approaches the end of its return movement.

4. In a punch press, a standard, a tubular column mounted therein, a plunger mounted: in .said column for vertical movement, an adjustable head mounted on the column, a die mounted in the head for vertical movement and contacting the upper end of the plunger, a punch mounted in the head above and in alinement with the die, a stripper mounted on the head for vertical reciprocation and adjacent the punch, lever means mounted in said standard for operating said plunger, and means connecting the stripper with said lever means for moving the stripper into inoperative position as the die is raised into operative relation to the punch and moving the stripper downwardly along the punch as the die approaches-the end ofV its return movement.

5. In a punch press construction, a standard, a tubular column carried by the standard, a plunger carried by the column and reciprocable therein, a head mounted upon the l' column and adjustable about the same, a die mounted in the head and having its under face in contact with the upper end of the plunger, a punchcarried by the head and disposed above and in alinement with the i rat L IOL Vlli die, lever means mounted in the standard,

operating connections between the plunger and the lever means, a stripper associated with the punch and mounted for vertical reciprocation, operating connections between the stripper and said lever means acting to raise the stripper into inoperative position as the die is raised into operative relation to the punch and to move the stripper down wardly along the punch as the die approaches the end of its return movement, the plunger having an axial opening therein for receiving the slugs from the die, and the plunger having an outlet adjacent its lower portion through which the slugs are discharged.

6. In a punch press, a standard carrying a tubular column, a plunger mounted in the column tor reciprocation therein, a head mounted upon the column and adjustable about the same, a die mounted in the head and having its under face in contact with the upper end of the plunger, a punch carried by the head and disposed above and in alinement with the die, an operating lever mounted on the standard, operating connec tions between the plunger and the lever, a stripper mounted for vertical reciprocation and having stripping elements disposed ad* jacent the punch at opposite sides thereof, and operating connections between the stripper and said operating lever acting to operate the stripper similarly to the die, the plunger having an axial opening therein providing a reservoir for receiving the slugs punched by the die, said plunger having an opening at its lower portion through which the slugs may pass and be discharged from the press.

In witness whereof, I hereunto subscribe my name this 20th day of May, 1929.

ERNEST SASS. 

